System, method and computer accessible medium for determining eye motion by imaging retina and providing feedback for acquisition of signals from the retina

ABSTRACT

The human eye is constantly in motion. For many imaging applications in the eye, eye motion on the time scale of the image acquisition distorts the images. For imaging applications where the signal is very low, image distortion is so severe that imaging is impossible. According to an exemplary embodiment of the present disclosure, systems, methods and computer-accessible medium can be provided to determine eye motion in real time, and provide real time correction of the eye motion for secondary imaging methods to provide stable images and permit long integration times of single images to increase the signal to noise.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application relates to and claims priority from U.S. Patent Application No. 61/856,129, filed on Jul. 19, 2013, U.S. Patent Application No. 61/934,294 filed on Jan. 31, 2014, and U.S. Patent Application No. 61/934,998, filed on Feb. 3, 2014, the entire disclosures of which are incorporated herein by reference.

FIELD OF THE DISCLOSURE

Exemplary embodiments of the present disclosure relate to system, method and computer accessible medium for determining eye motion by imaging retina and providing active feedback for stable optical acquisition of signals from the retina.

BACKGROUND INFORMATION

Several techniques are available for creating images of the retina. One of conventional methods is identified as a fundus photography, where a full-field image of the retina is obtained by flood illumination. Another well-known method for such image generation is a scanning laser ophthalmoscopy (SLO) procedure. For example, SLO utilizes horizontal and vertical scanning mirrors to scan a specific region of the retina and create raster images. SLO imaging relies on the principle of confocal microscopy. The light is focused on the retina, and the reflected light is imaged back onto a pinhole to reject the out of focus light reflected from the eye. Due to their confocal nature, images generated by SLO show a higher contrast than fundus photos. Another difference is that eye movements during acquisition of a single frame likely results in geometric distortions of the resulting image. In fundus photographs, motion during illumination results in a blurred image.

For example, images generated by SLO have been used to monitor eye motion, and provide feedback to correct for eye motion in, e.g., optical coherence tomography (OCT) imaging. In such exemplary OCT setup, a newly acquired frame is compared to a reference frame and the displacement that minimizes the difference between these two frames is assumed to optimally correct the motion of the eye. However, as indicated above, eye movements during the acquisition can produce geometric distortions of the acquired image. As the acquisition of a single frame requires, e.g., approximately 30 milliseconds, these distortions may frequently occur. Such distortions, therefore, have a negative impact on the tracking ability of the system, especially if these eye movements occur during the acquisition of the reference frame. Since subsequent frames are generally compared to the reference frame to determine the eye motion, the distortions in the current frame or the reference frame can lead to the incorrect motion determination and the incorrect motion correction signals to the secondary imaging modality.

The tracking speed of SLO-based eye tracking is generally limited by its frame rate. However, sub-frames may be used instead of full-frames, thereby likely increasing the tracking speed. Due to the employed scanning mechanism of SLO, these sub-frames are obtained by either horizontally or vertically dividing the full frame into sub-frames. Such rectangular sub-frames can cover different parts of the retina. This can result in a different performance in horizontal and vertical directions (depending on the orientation of the rectangular sub-frame). Further, the performance would then depend on which sub-frame is being analyzed, because some parts of the retina contain more cues for the displacement estimation than other parts.

Accordingly, there may be a need to address at least some of the above-described deficiencies.

SUMMARY OF EXEMPLARY EMBODIMENTS OF PRESENT DISCLOSURE

Exemplary embodiments of the present disclosure address at least some of such issues and/or deficiencies by providing exemplary systems, methods and computer accessible medium which can be used to determining eye motion by imaging retina and providing active feedback for stable optical acquisition of signals from the retina.

For example, using such exemplary systems, methods and computer accessible medium, it is possible to acquire subsampled full-field images and using these subsampled images to build a reference frame, and determine eye movement. A full image resolution image can include a continuous grid of acquired pixels. Thus, these exemplary subsampled images can include a pattern of sparsely distributed pixels within the two-dimensional grid of illuminated and recorded spots. According to one exemplary embodiment, after every acquisition or at least most of the acquisitions, which may take less than one millisecond, the pattern can be changed and a new subsampled image can be acquired. Movement during the acquisition of a subsampled image according to the exemplary embodiment of the present disclosure can be small due to the fast acquisition speed, and such movements would likely not degrade the geometric integrity of the image.

Further, the subsampled images can be used in the following exemplary ways, but are not limited thereby. First, e.g., a full resolution reference image can be obtained by registering and combining multiple subsampled images. Second, e.g., the subsampled image can be compared to the reference image, and the detected optimal displacement can produce the motion estimation and the motion correction signals.

The system, method and computer-accessible medium according to an exemplary embodiment of the present disclosure can use, e.g., a digital light modulator (DLP) to create a pattern of small spots on the retina. For example, a pattern of small spots can be recorded by a 2 dimensional detector. The pattern of light spots can be altered for subsequent images acquired by the two-dimensional array, such that after a certain number of images, a partial or full image of the retina is acquired. The exemplary pattern of light spots can be acquired in such manner that the motion in between subsequent images can be determined and corrected for. After the acquisition of a partial or full image of the retina, this image can be used as a reference image. Individual images consisting of a pattern of small dots on the retina are correlated with the reference image to determine eye motion with respect to the reference image. The acquisition of an image including a pattern of small dots can be very fast, e.g., on the time scale of milliseconds to microseconds, providing very fast feedback on the eye motion.

The eye motion information can be used in a secondary imaging system, such as, e.g., an Optical Coherence Tomography system or a fluorescence detection system, to stabilize the secondary imaging system with respect to eye motion. The exemplary stabilization can be performed by sending motion correction signals to a galvanometer system such that the galvo system provides a stabilized image of the retina.

These and other objects, features and advantages of the present disclosure will become apparent upon reading the following detailed description of exemplary embodiments of the present disclosure, when taken in conjunction with the appended drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects, features and advantages of the present disclosure will become apparent from the following detailed description taken in conjunction with the accompanying drawings showing illustrative embodiments of the present invention, in which:

FIG. 1 is a block diagram of a system according to an exemplary embodiment of the present disclosure, which also illustrates exemplary flow of data;

FIG. 2 is a schematic diagram of an optical layout/configuration according to a further exemplary embodiment of the present disclosure which can be included with and/or utilized with the exemplary system shown in FIG. 1;

FIG. 3 is a flow diagram of a method according to an exemplary embodiment of the present disclosure which can be executed by one or more components of the system shown in FIG. 1;

FIG. 4 is a block diagram of the system according to another exemplary embodiment of the present disclosure, which also illustrates exemplary flow of data;

FIG. 5 is a block diagram of the system according to yet another exemplary embodiment of the present disclosure, which also illustrates exemplary flow of data, in a differential mode;

FIG. 6 is a block diagram of the system according to still yet another exemplary embodiment of the present disclosure, which also illustrates exemplary flow of data, with motion correction feature(s);

FIG. 7 is a further schematic diagram of an optical layout/configuration according to a further exemplary embodiment of the present disclosure;

FIG. 8 is a set of exemplary images of generated images according to an exemplary embodiment of the present disclosure; and

FIG. 9 is an illustration of an exemplary block diagram of an exemplary system in accordance with certain exemplary embodiments of the present disclosure.

Throughout the drawings, the same reference numerals and characters, if any and unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the subject disclosure will now be described in detail with reference to the drawings, it is done so in connection with the illustrative embodiments. It is intended that changes and modifications can be made to the described exemplary embodiments without departing from the true scope and spirit of the subject disclosure and appended claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

A block diagram of an system according to an exemplary embodiment of the present disclosure is shown in FIG. 1, which also illustrates an exemplary data flow. For example, as shown in FIG. 1, light or other electro-magnetic radiation(s) from a secondary imaging system (110) and an eye tracker imaging system (160) can be combined by a beam splitter (130). The light/radiation(s) can be reflected on a retina (140), and the reflected light/radiation(s) can be transmitted into both imaging systems (110), (160). The eye tracker imaging system (160) can include a digital micro-mirror device (DMD) array, which can facilitate subsampling a full-field image of the retina and is further described below. The resulting image is digitized by a frame grabber (210) and the subsampled frame (200) is send to the motion estimation system (190).

This exemplary system of FIG. 1 can be configured to compare the subsampled frame to a reference frame (180), stored in a buffer (170) to estimate the relative motion in the subsampled frame. This detected motion can then be transmitted in a digital format to a signal conversion system (150), which can transform the detected motion into a driving signal to compensate for such detected motion. Further, the driving signal can be provided for and/or coupled into a device to optically compensate and/or correct for the motion (120), for example, by using galvo-mirrors. Alternatively or in addition, the signal can be transmitted to the secondary imaging system (110), e.g., to directly offset its scanning mirrors to compensate for the detected motion.

Exemplary Components

i. Description of Exemplary Setup/Configuration

FIG. 2 shows a schematic diagram of an exemplary setup/configuration of optical components (e.g., Digital light projection—“DLP”—components) which can be used with the exemplary system illustrated in FIG. 1, and further exemplary systems provide din other figures, and described herein. It should be understood that the components described herein below are merely exemplary and other components and/or optics can be used to achieve same or similar results according to various exemplary embodiments of the present disclosure.

Exemplary Light Source

The exemplary imaging system configuration shown in FIG. 2 can use, e.g., a high-powered light-emitting diode (LED) (310) with center of spectral emission at about 850 nm and spectral bandwidth (e.g., about 50%) of approximately 30 nm. The LED (310) can have an active emitting area of about 1×1 mm², and a cone half angle of ±60 degrees. The light or radiation source (e.g., the LED (310)) can have a typical output power of, e.g., above 530 mW. The light/radiation(s) generated by the light/radiation source (310) can be collimated with an aspheric lens (320) (f=25 mm) to create a homogenous beam. To remove the structure in from the LED surface, a light pipe can be used.

Exemplary Optical Elements

The collimated light/radiation(s) from the LED (310) can be divided with a beam splitter (BS) (330). This exemplary BS (330) can reflect about 90% of the light, and transmit about 10% in the wavelength range of, e.g., approximately 700 nm to 1100 nm. The exemplary purpose for a high reflectance can be to direct as much as light/radiation(s) as possible to the detector arm. In the illumination path, about 90% of the light/radiation(s) can be guided to a beam dump.

To illuminate the digital micromirror device (DMD) (420), a total internal reflection (TIR) prism (370) can be used after splitting the beam. This exemplary prism (370) can include, e.g., two parts that are glued together leaving a small gap between them, approximately 10 μm causing the light/radiations(s) to have a total reflection inside the prism (370) when the critical angle is reached. This facilitates the beam to travel through the prism (370) with a minimal offset when reflecting from the mirror elements and the angle between the incoming and outgoing beam(s) can be approximately 90 degrees. The two telescopes (380), (390)/(340), (350) for relaying the retinal image (400),(410) to a detector (360), e.g., CMOS are shown in FIG. 2. The exemplary spot-size in the retina can be, but not limited to, e.g., about 6.84 um.

Exemplary Digital Light Projection (DLP) Procedure

Digital light projection (DLP) is a spatial light modulation technique which can be used in, e.g., cinemas, digital projectors and projection televisions. According to one exemplary embodiment of the present disclosure, one component in an exemplary DLP system is the digital micromirror device (DMD) which can include or be an optical semiconductor acting as a light switch. The exemplary DMD can include, e.g., several thousands of microscopic mirror elements that can be turned ON or OFF by tilting them (e.g., typically tilting angle about 10 or 12 degrees). The bit-streamed image code entering the semiconductor can direct each mirror to switch on and off up to several thousand times per second.

The DLP technology can be used in the systems according to various exemplary embodiments of the present disclosure to, e.g.: a) replace the mechanical scanning mirrors for light steering and to have total control of the light, b) simultaneously image multiple spots to the retina by switching several mirror elements ON, and/or c) provide a high-speed imaging system to image the retina. One of the exemplary advantages of using multiple spots for imaging can be that the imaging speed can be significantly increased compared to the use of a scanning laser ophthalmoscope (SLO), where one spot can be raster scanned over the retina (imaging speed is limited by scanning mirrors). To maintain confocality, not every mirror element in the array needs to be or should be turned on (e.g., in one example, every one out of 10 or one out of 100 elements can be turned on). This exemplary procedure/configuration can reduce and/or minimize a signal contribution from neighboring mirror elements. The light/radiation(s) reflected back from the retina can pass or provided through the same mirror element, making such mirror element to act as a spatial filter. An exemplary confocal imaging system can be provided with each mirror element acting as a pinhole like in SLO. The exemplary systems can maintain confocality, and also, simultaneously, acquire (in parallel) multiple spots that can form a subsampled image that can be substantially free from image distortion.

The DLP system according to an exemplary embodiment of the present disclosure can be divided to two main components/configurations, e.g., (a) a first DLP board that can includes most or all of the electronics to control the microscopic mirror elements, and (b) a second DMD board which can include the rectangular mirror array. For the exemplary imaging system, according to one exemplary embodiment of the present disclosure, it is possible to use a V4100 DLP system (ViALUX, Germany).

The exemplary flow of the data in the DLP system according to the exemplary embodiment of the present disclosure is shown in FIG. 3. For example, in this exemplary embodiment, a first DLP Board (520) can have a 32 GBit on-board memory storing up to 43690 XGA patterns, which can be delivered to a second DMD board (510) (or to PC) with a speed of about 24 Gbit/s. In one example, sequences of patterns can be generated in the second DMD board (510) (or the PC), and uploaded to the on-board memory (e.g., 32 Gbit SDRAM) via compressed USB2.0 transfer. This can facilitate a DMD control with, e.g., a 22 kHz mirror switching rate using optimized FPGA logic of the first DLP Board (520). The exemplary optimized FPGA logic can provide a triggered transfer of SDRAM data to the DMD array with, e.g., 24 Gbit/s data rate. Lossless, on-the-flight compression provides an effective USB transfer rate of 1.2 Gbit/s. The rectangular mirror array can contain, e.g., 1024×768 elements that can be about 13.6 μm in size each, providing a total area of about 14 mm×10.4 mm. The transmittance of the mirror array for 850 nm is approximately 84% for double pass of the light (mirrors are shielded with a glass window). To control the DLP Board, ALP-4.2 Highspeed software (ViALUX, Germany) is used (510). The first DLP Board (520) can be externally triggered by, e.g., an external hardware (540) to synchronize the mirror on/off switching with data acquisition, e.g., with the CMOS detector.

Data Acquisition

A block diagram of an acquisition system according to another exemplary embodiment of the present disclosure is shown in FIG. 4. For example, as illustrated in the exemplary embodiment of FIG. 4, to collect the reflected light/radiation(s) from the retina, a high-speed area scan camera (610) can be used (e.g., Basler acA2040-180 km NIR). The 4.2 megapixels CMOS sensor chip can be using a global shutter to facilitate recording of most or all pixels in the imaging array simultaneously, thus likely avoiding or minimizing artifacts that can be present with a rolling shutter technology. Thus, e.g., the camera (610) can record multiple reflection spots from the retina, at the same time. The camera (610) has a native frame rate of about 180 frames per second (fps). This can be increased by using a pixel binning process, e.g., by combining the data in a group of pixels into a single pixel, such as a 2×2, a 3×3, etc. block, which can increase the effective sensitivity or reduce the noise present in the resultant pixel. To capture fast eye movements, a high frame rate can be used.

After the signals are detected, they can be recorded by a frame grabber (630) (NI PCIe-1473R) that can support, e.g., 10-tap, 80-bit image acquisition at about 20 MHz to 85 MHz clock frequency with two Camera Link slots, thus giving a total bandwidth of about 850 MB/s. The exemplary system of FIG. 4 (e.g., the frame grabber (630)) can include a user-programmable FPGA for on-board image pre-processing, which can reduce computational resources utilized for image analysis. Because the FPGA is a hardware resource, it can free CPU (640) to perform other operations. CPU intervention is not required to perform the analysis, and thus, the latency can be significantly reduced from preprocessed input to processed output (620).

Image Processing for Eye Motion

The resulting imaging data of this exemplary configuration of the system shown in FIG. 4 can include subsampled images. Subsequent images can be displaced by a fixed, pre-determined amount, provided by the scan patterns. The actual eye motion can be superimposed on this scanning motion. This exemplary procedure of obtaining the images for motion detection results in undistorted images (e.g., even in the presence of eye motion) can provide constant information in every frame for registration purposes, and can operate at a high speed.

In SLO-based eye trackers, images are generally acquired by scanning the region of interest along two axes (a slow axis and a fast axis). Scanning along the fast axis produces lines, and the slow axis scanning produces an image by combining multiple lines. This scanning procedure likely results in distorted images (such as shearing along the slow axis) when eye motion is present during acquisition. For high-speed eye tracking, eye motion estimation can be performed on a subset of the lines, resulting from scanning along the fast axis, in a full image. These subsets can be rectangular shaped, resulting in anisotropic information content that can be available for registration routines. In addition, the imaged region is moving over the imaged object. Because not all parts of the object have the same texture, this can result in varying levels of registration accuracy during a full cycle of the SLO's scanners.

The subsampled images can be used in various ways, according to exemplary embodiments of the present disclosure. For example, the subsampled images can be registered to a reference frame, to estimate motion relative to this reference frame. Further, a plurality of subsampled images can be combined to produce such a reference frame. This is further discussed herein below.

ii. Estimation of Movement Between Subsampled Frame and Reference Frame

Before motion correction signals to compensate motion can be determined, the motion should be detected. A registration of a subsampled image to the full-resolution reference image should be obtained. For example, the transformation parameters that can be found by the registration procedure can then be used for the compensation signal.

A large range of registration methods are available. For example, the subsampled image can be interpolated to obtain a full-resolution image, which can then be registered to the reference image. This registration can be done based on intensity-based error metrics such as the mean absolute difference between the two images, or the root-mean-square difference between the two images. Alternatively or in addition, the exemplary phase correlation methods (based on cross-correlation) can be used to obtain the transformation up to pixel accuracy. Post-processing may then be applied to get sub-pixel accuracy. To better handle illumination differences between the reference frame and the newly acquired images, normalized cross-correlation can be used, although at higher computational costs.

Alternatively or in addition, the full-resolution image can be subsampled (e.g., after appropriate filtering to reduce aliasing) after which, the subsampled image can be registered to the subsampled reference image. In this exemplary case, pixel accuracy relates to a pixel in the subsampled space, which can correspond to many pixels in the full-resolution image space. Therefore, a sub-pixel accuracy can generally be needed in this exemplary approach.

iii. Generation of Exemplary Reference Frame

The exemplary acquired images can be subsampled. This can mean that they sparsely cover the full field-of-view, but they have a low resolution. Due to the scanning introduced by the DLP, subsequent subsampled images can be displaced. For a static object, a full resolution image can be assembled from a series of subsampled images based on their known displacements. However, if the object is not static, the displacements between the images are not just induced by the scanning, but also by the motion of the object. This can occur in retinal images, when the eye is moving during the acquisition of the subsampled images.

One exemplary procedure for generating such reference frame includes initially assuming that there is no motion during the acquisition of a set of subsampled images that cover the full field. These subsampled images can then be combined into a full resolution image based on the induced displacements by the DLP. By repeating this exemplary procedure, the resulting full resolution images can be compared. Such exemplary images can be registered and averaged (e.g., by calculating, for every retinal location, the mean or median of all measurements). Alternatively or in addition, the exemplary images can be registered, and their agreement can be determined. By retaining those images that show a high correspondence, the images containing eye movement (e.g., which do not reoccur in the same way) can be rejected.

Another exemplary procedure can be used that does not require the assumption of a static retina. Instead, e.g., the subsampled images are registered with sub-pixel accuracy. Such procedure uses a registration accuracy that matches the amount of subsampling that has been used. These registration procedures are generally known. The resulting transformation parameters can then be used to align all subsampled images in a full resolution frame. Any pixel that does not contain measurement data should be estimated from surrounding pixels. Alternatively or in addition, such pixels may be flagged and excluded from use in further processing.

iv. Exemplary Variations

Exemplary Drift and Differential Mode

An exemplary embodiment of the present disclosure as described herein can utilize a fixed reference frame, e.g., with displacements that are expressed in absolute units. This has certain consequences: First, there can be a small drift in the image over the time period of tracking. If, for example, illumination changes over time, then there may no longer be a geometrical transformation that coincides with the minimum difference between the reference image and the registered image. This can be solved (e.g., at least partially) by processing the images before registration (for example, by filtering out low spatial frequencies) or by using more robust error metrics in the registration routine. Second, the displacements as determined with the eye tracking system should be translated into displacements of the secondary imaging system. Thus, the calibration of the two imaging systems should be performed. For example, the measured displacement can be converted into a signal that exactly nullifies this displacement as measured by the secondary imaging system, e.g., by utilizing a differential system according to another exemplary embodiment of the present disclosure.

In such further exemplary embodiment, the differential system (shown in FIG. 5) can include the same or similar components as those provided in the exemplary system of FIG. 1 the system as well as other component, the correction of the displacement can be performed in the common imaging path of both systems (110), (160). The corrected displacements in this exemplary embodiment of the system can also affect the images acquired by the eye tracker. As a result, an eye tracking system (160) of this exemplary system can determine the differential or residual motion, e.g., the motion that is present in addition to the motion that was detected before. According to such exemplary embodiment, the motion correction itself should operate in an integrating mode, which can be implemented in the signal conversion or in the motion correction hardware. In this embodiment, no calibration between the two imaging systems is required. Thus, both the eye tracking system (160) and the secondary imaging system (110) can be used to review the motion-compensated image, so only differential motion is observed.

Exemplary Motion Correction Through Secondary Imaging System

According to yet another exemplary embodiment of the present disclosure, motion correction can be performed by certain exemplary optical components, such as, e.g., galvanometer based mirrors. In certain exemplary cases, however, the secondary imaging modality already contains components to steer the imaging system. This may be facilitated due to either the mirrors that control the location of the beam in a scanning setup, or components that steer the field of view. In either case, the system according to a further exemplary embodiment of the present disclosure, as shown in FIG. 6, can use such components in the secondary imaging system (110) to compensate for the determined motion. In this exemplary embodiment, the eye tracking system (160) can communicated with the secondary imaging system (110) via a displacement signal, which can then be superimposed on the steering signal of the secondary imaging system (110). This exemplary configuration and/or procedure can reduce the number of components in the setup.

FIG. 7 illustrates a further exemplary implementation of an exemplary system, according to an exemplary embodiment of the present disclosure. Light from an exemplary lightsource 760 can be collimated by lens 250 to create a collimated beam. The lightsource 760 can be for instance a Light Emitting Diode (LED) or a laser. The light can be reflected by the DMD 770, where a sparse number of mirror elements can be turned on. The light reflected from the mirror elements that can be turned on can optionally pass through a polarizer 780 and can be collimated by lens 450. Light can pass through a beam splitter 550. The beam splitter 550 can be or include a polarizing beam splitter. The polarizer 780 can be configured to polarize the light or other electromagnetic radiation such that it can be transmitted by the polarizing beam splitter 550. The light or other electromagnetic radiation can pass through lens 850, which can create an image of the DMD 350. After the lens 850, the light or other electromagnetic radiation can be collimated again by lens 950. Lens 950 can create a beam for every mirror element that was turned on that can pass through the pupil of an eye. Following the lens 950, an optional quarter wave plate 1050 can be provided. The quarter wave plate 1050 can turn the linearly polarized light into circularly polarized light. The circularly polarized light or other electromagnetic radiation can be focused on the retina by the eye. The reflected light or other electromagnetic radiation from the retina can propagate back through the eye towards the quarter wave plate 1050, which can turn the reflected light back into linearly polarized light that can be orthogonal to the polarization of the light that was incident on the quarter wave plate propagating towards the eye. The light can propagate back through lens 950 and lens 850 before it can be incident on beamsplitter 550. The light can be reflected by beam splitter 550 towards lens 650 and camera 750.

FIG. 8 shows a set of exemplary images illustrating the creation of an exemplary image. An exemplary target was a section of monetary note. FIG. 8 shows an exemplary wide field image, which can be created by turning all mirror elements on. A confocal image of the retina can be created by creating a spot pattern on the DMD. The spot pattern reflected by the eye is recorded by the camera. Virtual pinholes can be to the camera image, where all light can be discarded that can fall on camera pixel elements that may not correspond to the image of a mirror element that was turned on. FIG. 8 further illustrates the applied virtual pinholes and the final image that is recorded after summing 1, 50 and 100 spot patterns. In this example 100 spot patterns correspond to the case where all mirror elements of the DMD were turned on once in the spot pattern sequence. The exemplary number of spot patterns can be larger or smaller than the example of 100 spots shown in FIG. 8. For example, multiple spots can be acquired in parallel for each captured image from the camera.

FIG. 9 shows a block diagram of an exemplary embodiment of a system according to the present disclosure. For example, exemplary procedures in accordance with the present disclosure described herein can be performed by a processing arrangement and/or a computing arrangement 902. Such processing/computing arrangement 902 can be, for example entirely or a part of, or include, but not limited to, a computer/processor 904 that can include, for example one or more microprocessors, and use instructions stored on a computer-accessible medium (e.g., RAM, ROM, hard drive, or other storage device).

As illustrated in FIG. 9, for example a computer-accessible medium 906 (e.g., as described herein above, a storage device such as a hard disk, floppy disk, memory stick, CD-ROM, RAM, ROM, etc., or a collection thereof) can be provided (e.g., in communication with the processing arrangement 902). The computer-accessible medium 906 can contain executable instructions 908 thereon. In addition or alternatively, a storage arrangement 910 can be provided separately from the computer-accessible medium 906, which can provide the instructions to the processing arrangement 902 so as to configure the processing arrangement to execute certain exemplary procedures, processes and methods, as described herein above, for example.

Further, the exemplary processing arrangement 902 can be provided with or include an input/output arrangement 914, which can include, for example a wired network, a wireless network, the internet, an intranet, a data collection probe, a sensor, etc. As shown in FIG. 9, the exemplary processing arrangement 902 can be in communication with an exemplary display arrangement 912, which, according to certain exemplary embodiments of the present disclosure, can be a touch-screen configured for inputting information to the processing arrangement in addition to outputting information from the processing arrangement, for example. Further, the exemplary display 912 and/or a storage arrangement 910 can be used to display and/or store data in a user-accessible format and/or user-readable format.

The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. Indeed, the arrangements, systems and methods according to the exemplary embodiments of the present disclosure can be used with and/or implement any OCT system, OFDI system, SD-OCT system or other imaging systems, and for example with those described in International Patent Application PCT/US2004/029148, filed Sep. 8, 2004 which published as International Patent Publication No. WO 2005/047813 on May 26, 2005, U.S. patent application Ser. No. 11/266,779, filed Nov. 2, 2005 which published as U.S. Patent Publication No. 2006/0093276 on May 4, 2006, and U.S. patent application Ser. No. 10/501,276, filed Jul. 9, 2004 which published as U.S. Patent Publication No. 2005/0018201 on Jan. 27, 2005, and U.S. Patent Publication No. 2002/0122246, published on May 9, 2002, the disclosures of which are incorporated by reference herein in their entireties. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles of the disclosure and are thus within the spirit and scope of the present disclosure. It should be understood that the exemplary procedures described herein can be stored on any computer accessible medium, including a hard drive, RAM, ROM, removable disks, CD-ROM, memory sticks, etc., and executed by a processing arrangement and/or computing arrangement which can be and/or include a hardware processors, microprocessor, mini, macro, mainframe, etc., including a plurality and/or combination thereof. In addition, certain terms used in the present disclosure, including the specification, drawings and claims thereof, can be used synonymously in certain instances, including, but not limited to, e.g., data and information. It should be understood that, while these words, and/or other words that can be synonymous to one another, can be used synonymously herein, that there can be instances when such words can be intended to not be used synonymously. Further, to the extent that the prior art knowledge has not been explicitly incorporated by reference herein above, it can be explicitly incorporated herein in its entirety. All publications referenced herein can be incorporated herein by reference in their entireties. 

1. An apparatus for determining tracking a motion of at least one portion of an anatomical structure, comprising: at least one detector first arrangement which is configured to simultaneously detect a plurality of electromagnetic radiations which are provided from multiple points within the at least one portion, wherein the electromagnetic radiations are received in a confocal configuration; and at least one computer second arrangement which is configured to (i) obtain at least one reference first image of the at least one portion, and (ii) generate at least one sparsely-sampled second image of the at least one portion based on the detected electromagnetic radiations, wherein the second arrangement is further configured to determine the motion based on a comparison of the first and second images.
 2. The apparatus according to claim 1, wherein the anatomical structure is an eye, and wherein the second arrangement determines the motion of the at least one portion of the eye.
 3. The apparatus according to claim 1, wherein the second arrangement is configured to generate a plurality of the second images, and determine the motion based on the comparison between the first image and each of the plurality of second images.
 4. The apparatus according to claim 1, wherein the second arrangement includes at least one particular device which includes at least one of a field programmable gated array (FPGA) or a complex programmable logic device (CPLD), and wherein the determination of the motion is performed by the at least one particular device.
 5. The apparatus according to claim 1, further comprising a digital micromirror device (DMD) which at least one of (i) forwards a particular electromagnetic radiation to the at least one portion or (ii) provides the electromagnetic radiations from the at least one portion.
 6. The apparatus according to claim 1, further comprising at least one optical third arrangement which is controlled by the second arrangement to adjust at least one component of at least one of optical component of mechanical components thereof based on the motion.
 7. The apparatus according to claim 6, wherein the at least one component is adjusted to provide at least one further signal, and further comprising at least one computer fourth arrangement which is configured to generate a stabilized image of at least one of (i) the at least one portion or (ii) at least one further portion of the anatomical structure based on the at least one further signal.
 8. The apparatus according to claim 7, wherein the fourth arrangement is part of an optical coherence tomography system.
 9. The apparatus according to claim 7, wherein the stabilized image is substantially free of motion artifacts.
 10. The apparatus according to claim 6, wherein the at least one component is adjusted to provide a therapy to the at least one portion which is unaffected by the motion.
 11. The apparatus according to claim 6, wherein the at least one component is adjusted to provide at least one further signal to the second arrangement, and wherein the second arrangement is further configured to generate a stabilized image of at least one of (i) the at least one portion, or (ii) at least one further portion of the anatomical structure based on the at least one further signal.
 12. The apparatus according to claim 11, wherein the second arrangement is further configured to cause a generation of a further reference image based on the stabilized image, and determine the motion based on the comparison between the further reference image and the second image.
 13. The apparatus according to claim 1, further comprising at least one polarizer forwards a particular electromagnetic radiation to the at least one portion, wherein the plurality of electromagnetic radiations are associated with the particular electromagnetic radiation.
 14. The apparatus according to claim 13, wherein the particular electromagnetic radiation is provided via a digital micromirror device.
 15. A method for determining tracking a motion of at least one portion of an anatomical structure, comprising: simultaneously detecting a plurality of electromagnetic radiations which are provided from multiple points within the at least one portion, wherein the electromagnetic radiations are received in a confocal configuration; and obtaining at least one reference first image of the at least one portion; generating at least one sparsely-sampled second image of the at least one portion based on the detected electromagnetic radiations; and using a computer hardware arrangement, determining the motion based on a comparison of the first and second images.
 16. The method according to claim 15, wherein the anatomical structure is an eye, and further comprising determining the motion of the at least one portion of the eye.
 17. The method according to claim 15, further comprising generating a plurality of the second images, and wherein the computer hardware arrangement is further configured to determine the motion based on the comparison between the first image and each of the plurality of second images.
 18. (canceled)
 19. The method according to claim 15, further comprising (i) forwarding a particular electromagnetic radiation to the at least one portion using a digital micromirror device (DMD), forwarding the particular from a polarizer to the at least one portion, wherein the plurality of electromagnetic radiations are associated with the particular electromagnetic radiation or (iii) providing the electromagnetic radiations from the at least one portion using the DMD.
 20. The method according to claim 15, further comprising adjusting at least one component of at least one of optical component of mechanical components thereof based on the motion.
 21. The method according to claim 20, further comprising adjusting the at least one component to provide at least one further signal, and generating a stabilized image of at least one of (i) the at least one portion or (ii) at least one further portion of the anatomical structure based on the at least one further signal. 22-24. (canceled)
 25. The method according to claim 20, further comprising adjusting the at least one component to provide at least one further signal, and generating a stabilized image of at least one of (i) the at least one portion, or (ii) at least one further portion of the anatomical structure based on the at least one further signal.
 26. The method according to claim 25, further comprising causing a generation of a further reference image based on the stabilized image, and determining the motion based on the comparison between the further reference image and the second image. 27-28. (canceled) 